Carroll, jr
process for preparing extruded  cellulosic film and
sheeting having excellent optical properties

ABSTRACT

A PROCESS IS DISCLOSED FOR PREPARING EXTRUDED CELLULOSIC FILM AND SHEETING HAVING EXCELLENT CLARITY AND OTHER OPTICAL PROPERTIES WHICH ARE SUBSTANTIALLY FREE OF DIE LINES AND SIMILAR DIE IMPERFECTIONS. THE EXTRUDED CELLULOSIC FILMS AND SHEETING ARE EXTRUDED AS A TRILAMINATE WITH THE CENTER LAYER OF THE TRILAMINATE BEING THE CELLULOSIC LAYER. THE OUTER LAMINA WHICH COVERS BOTH SIDES OF THE CELLULOSIC LAYER IS OF A DISSIMILAR AND INCOMPATIBLE THERMOSPLASTIC MATERIAL SUCH AS POLYETHYLENE. AS THE TRILAMINATE FLOWS THROUGH THE DIE THE OUTER THERMOPLASTIC LAYERS PREVENT THE INNER CELLULOSIC LAYER FROM CONTACT WITH THE LIPS OF THE DIE. AFTER EXTRUSION, THE OUTER LAMINA CAN BE STRIPPED FROM THE CELLULOSIC CENTER OR INNER LAMINA THEREBY PROVIDING AN EXTRUDED CELLULOSIC SHEET OR FILM FREE OF DIE MARKS AND WHICH HAS EXCELLENT CLARITY.

DEFENSIVE PUBLICATION UNITED STATES PATENT- OFFICE Published at the request of the applicant or owner in accordance with the Notice 0! Dec. 16, 1969, 869 0.6. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading 0! each abstract indicates the number of pages of specification, including claims and sheets 0! drawings contained in the application as originally filed. The dies or these applications are available to the public tor inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Otfice makes no assertion as to the novelty or the disclosed subject matter.

PUBLISHED DECEMBER 3, 1974 T929,002 PROCESS FOR PREPARING EXTRUDED CELLU- LOSIC FILM AND SHEETING HAVING EXCEL- LENT OPTICAL PROPERTIES Max L. Carrol], Jr., 720 Teasel Drive, Apt. 14, Kingsport, Tenn. 37660 Filed July 16, 1973, Ser. No. 379,682 Int. Cl. B29f 3/10 US. Cl. 260-224 1 Sheet Drawing. 5 Pages Specification A process is disclosed for preparing extruded cellulosic film and sheeting having excellent clarity and other optical properties which are substantially free of die lines and similar die imperfections. The extruded cellulosic films and sheeting are extruded as a trilaminate with the center layer of the trilaminate being the cellulosic layer. The outer lamina which covers both sides of the cellulosic layer is of a dissimilar and incompatible thermoplastic material such as polyethylene. As the trilaminate flows through the die the outer thermoplastic layers prevent the inner cellulosic layer from contact with the lips of the die. After extrusion, the outer lamina can be stripped from the cellulosic center or inner lamina thereby providing an extruded cellulosic sheet or film free of die marks and which has excellent clarity.

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